TY - JOUR
T1 - Facile path for copper recovery from waste printed circuit boards via mechanochemical approach
AU - Liu, Kang
AU - Wang, Mengmeng
AU - Tsang, Daniel C.W.
AU - Liu, Lili
AU - Tan, Quanyin
AU - Li, Jinhui
N1 - Funding Information:
This research was supported by “ National Key Technology R&D Program of China ” ( 2018YFC1900101 ), “ National Natural Science Foundation of China ” ( 51908318 ), “ China Postdoctoral Science Foundation ” ( 2019T120104 ), and “ Hong Kong Research Grants Council ” ( PolyU 15222020 ).
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/10/15
Y1 - 2022/10/15
N2 - Recycling copper (Cu0) from waste printed circuit boards (PCBs) is a prevalent challenge. Here, we propose a new pathway and reveal mechanisms for recovering Cu0 from waste PCBs via a mechanochemical approach. The successful application of mechanical force avoids using inorganic acid in the Cu0 recovery process. Our work demonstrates that ferric chloride (FeCl3) was superior to ferric sulfate and ferric nitrate as a solid-phase reagent for Cu0 recovery due to chloride complexation. Under the induction of mechanical force, the Cu0 in the waste PCBs was oxidized by Fe3+ and complexed by Cl¯ to form a meta-stable cuprous chloride, which was susceptible to leaching in an acidic liquid-phase system constructed by hydrolysis of ferric salt. Further mechanism analysis reveals that in the mechanochemical solid-phase reaction, Cu0, metallic impurities, metal oxides, and carbon materials from waste PCBs could also reduce Fe3+ to Fe2+. The optimum conditions for Cu0 recovery from waste PCB powder with FeCl3 as a solid-phase reagent were: rotational speed of 500 rpm, Cu0:Fe3+ molar ratio of 1:20, and reaction time of 120 min, achieving the highest recovery of 99.6 wt%. This study presents a facile path for Cu0 recovery from waste PCBs for resource circulation.
AB - Recycling copper (Cu0) from waste printed circuit boards (PCBs) is a prevalent challenge. Here, we propose a new pathway and reveal mechanisms for recovering Cu0 from waste PCBs via a mechanochemical approach. The successful application of mechanical force avoids using inorganic acid in the Cu0 recovery process. Our work demonstrates that ferric chloride (FeCl3) was superior to ferric sulfate and ferric nitrate as a solid-phase reagent for Cu0 recovery due to chloride complexation. Under the induction of mechanical force, the Cu0 in the waste PCBs was oxidized by Fe3+ and complexed by Cl¯ to form a meta-stable cuprous chloride, which was susceptible to leaching in an acidic liquid-phase system constructed by hydrolysis of ferric salt. Further mechanism analysis reveals that in the mechanochemical solid-phase reaction, Cu0, metallic impurities, metal oxides, and carbon materials from waste PCBs could also reduce Fe3+ to Fe2+. The optimum conditions for Cu0 recovery from waste PCB powder with FeCl3 as a solid-phase reagent were: rotational speed of 500 rpm, Cu0:Fe3+ molar ratio of 1:20, and reaction time of 120 min, achieving the highest recovery of 99.6 wt%. This study presents a facile path for Cu0 recovery from waste PCBs for resource circulation.
KW - Copper recovery
KW - Ferric salt
KW - Mechanochemical reaction
KW - Sustainable waste recycling
KW - Waste PCBs
UR - http://www.scopus.com/inward/record.url?scp=85135335625&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2022.129638
DO - 10.1016/j.jhazmat.2022.129638
M3 - Journal article
C2 - 35933860
AN - SCOPUS:85135335625
SN - 0304-3894
VL - 440
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 129638
ER -